塑性极限载荷分析法在圆筒接管开孔强度分析上的应用

THE APPLICATION OF PLASTIC LIMIT LOAD ANALYSIS IN A LARGE OPENING OF CERTAIN EQUIPMENT SHELL

选用大型通用有限元软件ANSYS对某筒体大开口模型进行了应力计算及评定,使用应力分类法对大开口处两条路径上的一次应力、一次加二次应力评定时,发现应力强度不能满足要求,依据JB 4732—1995(2005年确认)中的相关规定,对同一大开口模型进行了极限载荷分析,结果表明模型的设计内压小于最大允许内压,设计内压满足要求。由于应力分类法偏于保守,当对某些设备的局部部位进行强度校核时,在应力分类法不能通过的情况下,可使用塑性极限载荷分析法进行判定。

This paper makes stress calculation and assessment on the large opening model of certain shell through large general finite element software ANSYS.When using stress classification method to make assessment on the primary local membrane stress and the secondary stress on two paths of the large opening,the strength can't meet the requirement.According to the relevant regulations of JB4732—1995(confirmed in 2005),limit load analysis is made for the same large opening model.And the results indicate that the design internal pressure of the stress model is less than the maximal allowable internal pressure and the design internal pressure can meet the requirement.Since the stress classification method is comparatively conservative,plastic limit load analysis can be used to make assessment when the stress classification method doesn't work for strength check of local parts in some equipment.